This invention relates to a method of thermally curing a hydrophobic coating system including diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound provided on (directly or indirectly) a substrate of glass, plastic, ceramic, or the like, and a resulting coated article. The coating system may include one or more layers, and the DLC portion of the coating may be deposited on the substrate utilizing plasma ion beam deposition in certain embodiments.
Conventional substrates (e.g., glass) are susceptible to retaining water on their surfaces in many different environments, e.g., when used as automotive windows (e.g. backlites, side windows, and/or windshields) or as architectural/residential windows. When water is retained or collects on automotive windows, the water may freeze (i.e. forming ice). Additionally, the more water retained on a windshield, the higher power wiper motor(s) and/or wiper blade(s) required.
Thus, there exists a need in the art for a coated article (e.g. coated glass, ceramic or plastic substrate) that can repel water and/or dirt, and a method of making the same.
It is known to provide diamond like carbon (DLC) coatings on glass. U.S. Pat. No. 5,637,353, for example, states that DLC may be applied on glass. Unfortunately, the DLC of the ""353 patent would not be an efficient hydrophobic coating.
U.S. Pat. No. 5,250,322 to Takahashi et al., discloses a water-repellant coating including FAS on a glass substrate. Unfortunately, the water-repellant coatings of the ""322 patent may not be durable enough for certain applications (e.g., it may be prone to scratching, breaking down, etc. in automotive and/or other harsh environments).
In view of the above, it is apparent that there further exists a need in the art for a durable protective hydrophobic coating system that is somewhat resistant to scratching, damage, or the like.
It is a purpose of different embodiments of this invention to fulfill any or all of the above described needs in the art, and/or other needs which will become apparent to the skilled artisan once given the following disclosure.
Surprisingly, it has been found that by heating a fluoro-alkyl silane (FAS) compound inclusive layer applied on a diamond-like carbon (DLC) inclusive layer, the bond between the two layers may be strengthened and/or contact angle characteristics of the resulting coated article may be improved.
An object of this invention is to provide a method of thermally curing a hydrophobic coating system including diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound provided on (directly or indirectly) a substrate of glass, plastic, ceramic, or the like, and a resulting coated article.
Another object of this invention is to provide a method of thermally curing a hydrophobic coating system including diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound provided on (directly or indirectly) a substrate wherein the coating system is heated during the curing process to an extent sufficient to increase an initial contact angle of the resulting coated article and/or increase contact angle stability of the resulting coated article upon its exposure to material(s) such as hexane and/or isopropyl alcohol.
Another object of this invention is to provide a method of thermally curing a hydrophobic coating system including diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound provided on (directly or indirectly) a substrate, wherein the coating system is heated during the curing process to an extent sufficient to reduce the amount that the resulting article""s contact angle will go down upon exposure to material(s) such as hexane and/or isopropyl alcohol.
Another object of this invention is to provide a method of thermally curing a hydrophobic coating system including diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound provided on (directly or indirectly) a substrate, wherein the coating system is heated during the curing process to an extent sufficient to improve bonding of the FAS inclusive layer to an underlying DLC inclusive layer.
An object of this invention is to provide a durable coated article that can shed or repel water (e.g. automotive windshield, automotive backlite, automotive side window, architectural window, bathroom shower glass, residential window, bathroom shower door, coated ceramic article/tile, etc.).
Another object of this invention is to provide a hydrophobic coating system including one or more diamond-like carbon (DLC) inclusive layers.
Another object of this invention is to provide a hydrophobic coating system including each of DLC and FAS, the DLC being provided for durability purposes and the FAS for increasing the contact angle of the coating system.
Yet another object of this invention, in embodiments where a hydrophobic coating system includes multiple DLC inclusive layers and at least one FAS layer, is to form (e.g., via ion beam deposition techniques) a first underlying DLC inclusive layer using a first precursor or feedstock gas and a second DLC inclusive layer over the first underlying DLC inclusive layer using a second precursor or feedstock gas. The FAS inclusive layer may then be applied over the DLC layers in any suitable manner and then thermally cured in a manner so as to improve bonding of the FAS inclusive layer to the DLC inclusive layer and/or to improve contact angle characteristics of the resulting coated article. In certain embodiments, the first underlying DLC inclusive layer may function as an anchoring and/or barrier layer while the second or overlying DLC inclusive layer may be more scratch resistant (i.e., harder) and/or more dense so as to improve the coated article""s durability and/or scratch resistance.
Another object of this invention is to provide a coated substrate, wherein a coating system includes sp3 carbon-carbon bonds and FAS, and has a wettability W with regard to water of less than or equal to about 23 mN/m, more preferably less than or equal to about 21 mN/m, even more preferably less than or equal to about 20 mN/m, and in most preferred embodiments less than or equal to about 19 mN/meter. This can also be explained or measured in Joules per unit area (mJ/m2).
Another object of this invention is to provide a coated substrate, wherein a coating system includes sp3 carbon-carbon bonds and thermally cured FAS, the coating system having a surface energy xcex3C (on the surface of the coated article) of less than or equal to about 20.2 mN/m, more preferably less than or equal to about 19.5 mN/m, and most preferably less than or equal to about 18 mN/m.
Another object of this invention is to provide a coated substrate, wherein a DLC and FAS inclusive coating system has an initial (i.e. prior to being exposed to environmental tests, rubbing tests, acid tests, UV tests, or the like) water contact angle xcex8 of at least about 80 degrees, more preferably of at least about 100 degrees, even more preferably of at least about 110 degrees, and most preferably of at least about 125 degrees.
Another object of this invention is to provide a coated glass article wherein a DLC and FAS inclusive coating system protects the glass from acids such as HF, nitric, and sodium hydroxide.
Another object of this invention is to provide a coating system for a substrate that is abrasion resistant.
Another object of this invention is to manufacture a coated article having hydrophobic qualities wherein the temperature of an underlying glass substrate may be less than about 200xc2x0 C., preferably less than about 150xc2x0 C., most preferably less than about 80xc2x0 C., during the deposition of a DLC and FAS inclusive coating system. This reduces graphitization during the deposition process, as well as reduces detempering and/or damage to low-E and/or IR-reflective coatings already on the substrate in certain embodiments.
Yet another object of this invention is to fulfill any and/or all of the aforesaid objects and/or needs.
This invention fulfills any and/or all of the aforesaid objects and/or needs by providing a method of making a coated article comprising the steps of:
providing a substrate;
forming a coating system on the substrate in a manner such that the coating system includes each of diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound; and
heating at least an FAS compound portion of the coating system to a temperature and for a period of time sufficient to increase an initial contact angle xcex8 of the resulting coated article.
This invention further fulfills any and/or all of the above described needs by providing a method of making a coated article comprising the steps of:
providing a substrate;
forming a coating system on the substrate in a manner such that the coating system includes each of diamond-like carbon (DLC) and at least one fluoro-alkyl silane (FAS) compound; and
heating at least an FAS compound portion of the coating system to a temperature of from about 50 to 300 degrees C.
This invention further fulfills any and/or all of the above described needs and/or objects by providing a method of making a coated article comprising the steps of:
providing a substrate;
forming a coating system on the substrate in a manner such that the coating system includes at least one diamond-like carbon (DLC) inclusive layer and at least one fluoro-alkyl silane (FAS) inclusive layer; and
heating at least the FAS inclusive layer of the coating system to a temperature and for a period of time sufficient to improve contact angle xcex8 stability of the resulting coated article.
This invention will now be described with respect to certain embodiments thereof, along with reference to the accompanying illustrations.